xref: /freebsd/usr.bin/lam/lam.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #ifndef lint
39 #endif /* not lint */
40 #include <sys/cdefs.h>
41 /*
42  *	lam - laminate files
43  *	Author:  John Kunze, UCB
44  */
45 
46 #include <sys/capsicum.h>
47 
48 #include <capsicum_helpers.h>
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #define	MAXOFILES	20
58 #define	BIGBUFSIZ	5 * BUFSIZ
59 
60 static struct openfile {	/* open file structure */
61 	FILE	*fp;		/* file pointer */
62 	short	eof;		/* eof flag */
63 	short	pad;		/* pad flag for missing columns */
64 	char	eol;		/* end of line character */
65 	const char *sepstring;	/* string to print before each line */
66 	const char *format;	/* printf(3) style string spec. */
67 }	input[MAXOFILES];
68 
69 static int	morefiles;	/* set by getargs(), changed by gatherline() */
70 static int	nofinalnl;	/* normally append \n to each output line */
71 static char	line[BIGBUFSIZ];
72 static char	*linep;
73 
74 static char    *gatherline(struct openfile *);
75 static void	getargs(char *[]);
76 static char    *pad(struct openfile *);
77 static void	usage(void);
78 
79 int
80 main(int argc, char *argv[])
81 {
82 	struct	openfile *ip;
83 
84 	if (argc == 1)
85 		usage();
86 	if (caph_limit_stdio() == -1)
87 		err(1, "unable to limit stdio");
88 	getargs(argv);
89 	if (!morefiles)
90 		usage();
91 
92 	/*
93 	 * Cache NLS data, for strerror, for err(3), before entering capability
94 	 * mode.
95 	 */
96 	caph_cache_catpages();
97 	if (caph_enter() < 0)
98 		err(1, "unable to enter capability mode");
99 
100 	for (;;) {
101 		linep = line;
102 		for (ip = input; ip->fp != NULL; ip++)
103 			linep = gatherline(ip);
104 		if (!morefiles)
105 			exit(0);
106 		fputs(line, stdout);
107 		fputs(ip->sepstring, stdout);
108 		if (!nofinalnl)
109 			putchar('\n');
110 	}
111 }
112 
113 static void
114 getargs(char *av[])
115 {
116 	struct	openfile *ip = input;
117 	char *p, *c;
118 	static char fmtbuf[BUFSIZ];
119 	char *fmtp = fmtbuf;
120 	int P, S, F, T;
121 	cap_rights_t rights_ro;
122 
123 	cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT);
124 	P = S = F = T = 0;		/* capitalized options */
125 	while ((p = *++av) != NULL) {
126 		if (*p != '-' || !p[1]) {
127 			if (++morefiles >= MAXOFILES)
128 				errx(1, "too many input files");
129 			if (*p == '-')
130 				ip->fp = stdin;
131 			else if ((ip->fp = fopen(p, "r")) == NULL) {
132 				err(1, "%s", p);
133 			}
134 			if (caph_rights_limit(fileno(ip->fp), &rights_ro) < 0)
135 				err(1, "unable to limit rights on: %s", p);
136 			ip->pad = P;
137 			if (!ip->sepstring)
138 				ip->sepstring = (S ? (ip-1)->sepstring : "");
139 			if (!ip->format)
140 				ip->format = ((P || F) ? (ip-1)->format : "%s");
141 			if (!ip->eol)
142 				ip->eol = (T ? (ip-1)->eol : '\n');
143 			ip++;
144 			continue;
145 		}
146 		c = ++p;
147 		switch (tolower((unsigned char)*c)) {
148 		case 's':
149 			if (*++p || (p = *++av))
150 				ip->sepstring = p;
151 			else
152 				usage();
153 			S = (*c == 'S' ? 1 : 0);
154 			break;
155 		case 't':
156 			if (*++p || (p = *++av))
157 				ip->eol = *p;
158 			else
159 				usage();
160 			T = (*c == 'T' ? 1 : 0);
161 			nofinalnl = 1;
162 			break;
163 		case 'p':
164 			ip->pad = 1;
165 			P = (*c == 'P' ? 1 : 0);
166 			/* FALLTHROUGH */
167 		case 'f':
168 			F = (*c == 'F' ? 1 : 0);
169 			if (*++p || (p = *++av)) {
170 				fmtp += strlen(fmtp) + 1;
171 				if (fmtp >= fmtbuf + sizeof(fmtbuf))
172 					errx(1, "no more format space");
173 				/* restrict format string to only valid width formatters */
174 				if (strspn(p, "-.0123456789") != strlen(p))
175 					errx(1, "invalid format string `%s'", p);
176 				if (snprintf(fmtp, fmtbuf + sizeof(fmtbuf) - fmtp, "%%%ss", p)
177 				    >= fmtbuf + sizeof(fmtbuf) - fmtp)
178 					errx(1, "no more format space");
179 				ip->format = fmtp;
180 			}
181 			else
182 				usage();
183 			break;
184 		default:
185 			usage();
186 		}
187 	}
188 	ip->fp = NULL;
189 	if (!ip->sepstring)
190 		ip->sepstring = "";
191 }
192 
193 static char *
194 pad(struct openfile *ip)
195 {
196 	char *lp = linep;
197 
198 	strlcpy(lp, ip->sepstring, line + sizeof(line) - lp);
199 	lp += strlen(lp);
200 	if (ip->pad) {
201 		snprintf(lp, line + sizeof(line) - lp, ip->format, "");
202 		lp += strlen(lp);
203 	}
204 	return (lp);
205 }
206 
207 static char *
208 gatherline(struct openfile *ip)
209 {
210 	char s[BUFSIZ];
211 	int c;
212 	char *p;
213 	char *lp = linep;
214 	char *end = s + sizeof(s) - 1;
215 
216 	if (ip->eof)
217 		return (pad(ip));
218 	for (p = s; (c = fgetc(ip->fp)) != EOF && p < end; p++)
219 		if ((*p = c) == ip->eol)
220 			break;
221 	*p = '\0';
222 	if (c == EOF) {
223 		ip->eof = 1;
224 		if (ip->fp == stdin)
225 			fclose(stdin);
226 		morefiles--;
227 		return (pad(ip));
228 	}
229 	strlcpy(lp, ip->sepstring, line + sizeof(line) - lp);
230 	lp += strlen(lp);
231 	snprintf(lp, line + sizeof(line) - lp, ip->format, s);
232 	lp += strlen(lp);
233 	return (lp);
234 }
235 
236 static void
237 usage(void)
238 {
239 	fprintf(stderr, "%s\n%s\n",
240 "usage: lam [ -f min.max ] [ -s sepstring ] [ -t c ] file ...",
241 "       lam [ -p min.max ] [ -s sepstring ] [ -t c ] file ...");
242 	exit(1);
243 }
244